Hydraulically actuated load carrying apparatus



Sept. 6, 1966 R, J, MGCRACKEN 3,270,828

HYDRAULICALLY ACTUATED LOAD CARRYING APPARATUS Filed March 27, 1964 ,2 Sheets-Sheet l Sept. 6, 1966 R. J. MCCRACKEN 3,270,328

HYDRAULICALLY ACTUATED LOAD CARRYING APPARATUS 2 Sheets-Sheet 2 Filed March 27, 1964 n .Sm

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ROBERTJ. McCRAC KEN United States Patent O j 3,270,828 HYDRAULICALLY ACTUATED LOAD CARRYING APPARATUS Robert J. McCracken, Port .Ieiferson, N.Y., assignor to the United States of America as represented by the United States Atomic Energy Commission Filed Mar. 27, 1964, Ser. No. 355,515 7 Claims. (Cl. 1811-8) The present invention concerns a hydraulically actuated load carrying apparatus and more lparticularly a hydraulically actuated device capable of moving heavy loads within restricted areas.

In the movement of large and heavy objects within confined areas there are many problems which must be overcome. By a confined area is meant a location Where it is impossible or impractical to employ conventional lifting devices such as overhead cranes or mechanical lifting devices. An example of where this problem arises 4is at the Alternating Gradient Synchrotron located at the Brookhaven National Laboratory, Upton, New York.

This accelerator consists of a large number of heavy magnet sections and in certain locations, such as in the experimental area, heavy concrete shielding blocks are utilized to divide up the area into confined spaces where separate experiments may be conducted or equipment may be arranged and situated in preparation for experiments. Within these confined spaces 'it is `often necessary to bring in very heavy magnets or other pieces of equipment without disturbing adjacent areas where other work may be continuing.

Until the time when this invention was conceived and utilized it was necessary to employ rolling bars under steel plates to support the yload in each case and to ernploy a full crew of riggers who utilized Winches, ropes and jacks to move the heavy objects into the confined areas and locate same. This is an -extremely time consuming and expensive way of accomplishing this result but no other satisfactory way was known.

By the present invention it has been made possible to move heavy objects into 'confined locations conveniently, efficiently, relatively quickly as compared to previous methods, and economically. In accordance with this invention there is provided a pad or platform for supporting a load mounted through ball bearings on a plate. A ring surrounds the plate and is capable of supporting the platform independently of the plate. By the selective application of hydraulic pressure through appropriate apparatus it is possible to creep the load in a horizontal direction and to change the direction of movement at will.

It is thus a tirst object of this invention to provide for the movement of loads in confined areas.

It is another object of this invention to provide apparatus for the positioning of an object within a confined area.

Another object is to provide a compact arrangement for the remote handling and positioning of heavy objects.

Still another object is apparatus capable of positioning accurately and by remote control objects of vgreat weight and bulk.

Other objects and advantages of this invention will hereinafter become obvious from the following description of a preferred embodiment of this invention made with reference to the accompanying drawings in which: FIG. 1 is a top view of 'a preferred embodiment of this invention;

FIG. 2 is an elevation view along 2-2 of FIG. 1; FIG. 3 is a view along 3-3 of FIG. 1; FIG. 4 shows a portion of the apparatus positioned at a diiferent point in its operation; and

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FIG. 5 illustrates schematically the hydraulic arrangement for unloading the lifting piston.

Referring to FIGS. l and 2 there is shown apparatus 10 in accordance with this invention consisting of a load supporting platform 12 a ball bearing retaining plate 14, a bottom plate 16, and an annular base 18 surrounding plate 16. A load 20, shown in phantom, would be supported by platform 12 as illustrated.

Platform 12 is circular in shape and is provided on its underside with a cylindrical recess 22 in which a piston 24 having an O-ring 26 is placed for movement as will be described below. A retaining ring 28 limits the downward movement of piston 24 and liuid under pressure is supplied to the space above piston 24 by way of holes 34 and 36 and a threaded socket 38 for receiving the end of a fluid line (not shown). The outer surface of platform 12 is provided with an annular groove 42 for a purpose to be later described.

Platform 12 is supported normally that is when apparatus is not being used, lby base 18 through a ring or hooplike element 44. Base 18 has an 'elongated opening 45 in the center as shown in FIG. 1. Base 18 and ring 44 would be connected together by any convenient means such 'as by welding or bolting. Base 18 has an inner shoulder 46, and ring 44 has an inner shoulder 48 for annular plate 49. Platform 12 and ring 44 are joined together by a pair of flange rings 52 and 54. Flange ring 52 has a lip 56 extending into slot 42 of platform 12 and is clamped to ring 44 with bolts 58, 62, 64, 66 and 68. Flange ring 52 is provided with a grease fitting 72 as illustrated in FIG. 3 and holes 74 and 76 to distribute the grease to slot 42. Flange ring 54 is of similar construction having a grease fitting 78 shown in FIG. l.

Bottom plate 16 is provided with an insert 78 of suitable bearing material and has an annular shoulder 82 facing down which is located slightly above shoulder 46 of base 18. As best seen in FIG. 1, shoulder 82 overlaps shoulder 46 of ring 18 on opposite sides of opening 45 so that relative movement of plate 16 and ring 18 is limited to a direction parallel to the straight sides of opening 45. Above insert 78 is ball bearing retaining plate 14 which is provided with appropriate sockets for a plurality of ball bearings 84 which are free to rotate in any direction as is understood in the art. Ball bearings 84 rest on insert 78 thereby supporting plate 14 and extend above plate 14 to support piston 24 as shown. It will be seen that when pressurizing uid is injected by way of socket 38 and holes 36 and 34 into the space above piston 24 that platform 12 along with load 2G, annular ring 44 and base 18 will be raised so that support of load 20 will rest directly on bottom plate 16. When the space above piston 24 is relieved of fluid under pressure, then load 20 will be supported by base 18, and bottom plate 16, being unloaded, is capable of being pushed laterally with minimum force since it is under its own weight along with that of bearing retaining plate 14 and piston 24.

It will be seen that fixedly mounted on base 18 and oppositely situated thereon are a pair of hydraulic cylinders 86 and 88. Within each cylinder 86 and 88 is a `double acting hydraulic arrangement including a single piston (not shown) as is well known in the art. Extending from the piston (not shown) within cylinder 86 are a pair of cylindrical arms 92 and 94 which are threadably connected to a pair of clevises 96 and 98, respectively, to permit any necessary or desirable adjustments in length. Clevis 96 is pivotally connected to one end of a cross bar 102 by way of a pin 104. Clevis 98 is pivotally connected to one end of a cross bar 106 by way of a pin 108. Pins 104 and 108 pass through elongated slots (not shown) in cross bars 102 and 104 to permit misalignments due to small differences in movements. In

similar fashion, arms 112 and 114 extending from cylinder 8S are connected by way of clevises 116 and 118,y respectively, to cross bars 102 and 106. Cylinders 86 and SS are provided with the usual fittings (not shown) for the delivery and exhaust of hydraulic fluid under pressure to control the movement of the pistons within.

Cross bar 102 is provided at its center with a shaft assembly 126 which consists of a block 128 through which cross bar 102 passes and is pinned in place by a pin 132. Block 128 supports a threaded bucking bolt 134 illustrated and a plunger rod 136 which is held in place by a set screw 138. The position of bolt 134 is readily adjustable by rotati-ng it in lblock 128. The axis of plunger rod 136 is located in the horizontal plane in which is situated the central axes of hydraulic cylinders 86 and 88.

Plunger rod 136 extending from shaft assembly 126 passes through a bearing 142 to contact the side of bottom plate 16. When cross bar 102 is moved as a result of the action of hydraulic cylinders 86 and 83 plunger rod 136 will be moved as well, sliding in bearing 142.

Cross bar 106 is similarly provided with a shaft assembly 144, a bucking bolt 146 and a lplunger rod 148.` During hydraulic operation of the apparatus described, bucking bolts 134 and 146 are retracted as illustrated so as not to interfere with the movements of cross bars 102 and 106 and plunger rods 136 and 148. The function of bucking bolts 134 and 146 will be described further below.

Also mounted on ring 44 are a pair of identical cylindrical plunger bodies 152 and 154 which are disposed on opposite sides of bucking bolt 146. From plunger body 152 extends a cylindrical plunger shaft 156 which at the inner end normally contacts the outer surface of bearing retaining plate 14 and is free to slide axially except with the restrictions to be mentioned. The outer end of plunger body 152 has an end wall 15S. A collar 162 slidable within body 152 has an opening through which shaft 156 passes and a pin 164 is utilized to connected shaft 156 and collar 162 together so that they will move simultaneously. Thus a series of helical springs 166, 168 and 172 separated by washers 174 and 176 mounted between collar 162 and end wall 15S bias collar 162 and plunger 156 inwardly and the latter in continuous contact normally against ball bearing retaining plate 14 as illustrated. In the position shown, springs 166-172 are partially expanded because retaining plate 14 is shown exactly centered with respect to platform 12. Should the former be moved to the right then the aforementioned springs will be compressed further so that when retaining plate 14 is free to move it will be returned to its extreme position to the left in readiness for another cycle (as shown in FIG. 2). Plunger body 154 is similarly provided with a plunger shaft 170 biased against retaining plate 14.

Operation of shuffling foot assembly 10 is as follows:

Load 20 is placed on platform 12 as shown in phantom in an area where an overhead crane or other conventional lifting device may be used, prior to moving load 20 into the restricted area. As earlier mentioned, bucking bolts 134 and 146 are fully retracted. Load 20 is supported initially through ring 44 and base 13. No uid pressure is delivered to the upper side of piston 24 so that the latter is resting with its own weight only on bearings 84 which in turn are resting on bottom plate 16. Hence, the latter is supporting only its own weight, that of ball bearings 84, retaining plate 14 and that of piston 24. Hydraulic cylinders 86 and 83 are then energized by delivering fluid pressure to the same sides as plunger bodies 152 and 154 with the result that cross bars 102 and 106 are moved in the forward direction, that shown by arrow A. Plunger shaft 14S thus pushes bottom plate 16 in the same direction, while bearing retaining plate 14 is pushed by plunger shafts 156 and 178 in the same direction due to the expansion of the compressed springs 166, 16S and 172, so that at the end of this stroke bottom plate 16 has been moved transversely to the left relative to platform 12 while retaining plate 14 is located on the limiting side of plate 49 and is located with reference to plate 16 as shown in FIG. 4.

At the end of this first stroke fluid pressure is then delivered through socket 38 to the space atbove piston 24. This raises platform 12 with load 20 and base 18 ot the ground, hence shifting support for assembly 10 and load 20 directly to bottom plate 16. At that point, fluid -pressureto cylinders 86 and 88 is transferred to the opposite side from plunger bodies 152 and 154, reversing the direction of movement of cross bars 102 and 106 so that plunger shafts 134 and 148 move in the direction of arrow B, the former pushing against the side of bottom plate 16. However, since the latter is anchored iirmly to ground under the weight of assembly 10 and load 20, both of the latter move in the direction of arrow A, rolling on ball bearings 84. Retaining plate 14 will move only one half the distance moved by platform 12 and plunger bodies 152 and 154. Thus, at the end of this stroke, the plunger shafts 156 and 178 will be backed up against and compressing their respective springs so that when fluid pressure is relieved above piston 24, plungershafts 156 and 178, under the inuence of their biasing springs will push retaining plate 14 to a position limited by its retaining plate 49. Plate 16 is then pushed all the way over to the left as above in readiness for another cycle. The cycle is then repeated so as to shule load 20 forward into its desired position.

It should be understood that the weight of load 20 on platform 12 tends to drive the Huid out from above piston 24. However, as ring 18 comes down in touch with the ground the load supported by plate 16 is not fully relieved there being a tendency to balance out the load ove1 the two supporting elements. In order to insure a positive transfer of load and thus to insure effective control and decisive action of the apparatus, some means must be provided to unload piston 24 completely. This is accomplished in accordance With this invention by the arrangement shown in FIG. 5 where is shown schematically the arrangement for insuring eicient and positive movement of the apparatus just described. In it is illustrated lifting piston 24 mounted in its cylinder under platform 12. Fluid pressure is delivered to the space above piston 24 by way of a pump P1 through a valve arrangement 2012 in the direction of arrows C. Draining of uid away from piston 24 i-s accomplished in the direction and lines indicated by arrows D. Valve 202 under the action of a spring (not shown) is normally closed to ow indicated by arrows D and open to flow indicated by arrows C. A solenoid 204 upon being actuated closes ilow indicated by arrows C and opens ow indicated by arrows D. An ex haust pump P2 provides for a positive withdrawal of fluid pressure from above piston 24. A valve 206 which is normally closed is operated to be opened by a solenoid 208 which is set to open valve 206 a short time after solenoid 204 is actuated to reverse ow in valve 202.` This is an automatic time delay as is understood in the art. A line 212 by-passes valve 206 to the sump until valve 206 `is opened. A check valve 214 in line 212 permits flow only in direction D.

The arrangement illustrated in FIG. 5 operates as follows: Pump P1 supplies fluid under pressure through valve 202 open in this direction to the space above piston 24 to raise platform 12. When it is desired to release fluid pressure from above piston 24, solenoid 204 is actu ated to close valve 202 to ow in the C direction and open it to flow in the D direction. Due to the weight of load 20 most of the fluid drains out in the D direction through valve 202 and out to the sump through by-pass line 212. After .a finite interval of time following the actuation of solenoid 204, which is sufficient for most of the iluid pressure to be relieved, solenoid 208 is automatically actuated to open valve 206 which thereby permits pump P2 to suck out the last of the fluid over piston 24 with the result that plate 16 is completely unloaded making it easier to move the latter under the force of plunger 148 and retaining plate 14 under the forces of plungers 156 and 158. Check valve 214 prevents fluid from backing up from the sump when valve 206 is open. Solenoids 204 and 208 would then be deenergized in preparation for the next cycle. Pumps P1 and P2 are normally in operation during the Whole cycle as is understood in the art and may be motor driven.

When load 2i) reaches its final position, or close to it, the -arrangement described provides for an acc-urate, final adjustment, manually carried out. Cylinders 86 and 88 are depressurized and piston 24 is pressurized to raise base 18, and bucking bolts 134 and 146 are threaded into contact with ring 44 to move load 20 accurately into its iinal position. Jacks would be used to raise load 20 slightly to remove assembly if desired.

It will be noted that the apparatus just described is capable of moving load only in the direction of arrow A. Typically, when a load 20 is being moved into place, at least two .and possibly more assemblies 10 are utilized to support load 20. Ordinarily, under these conditions it would be difficult to change the direction of movement of load 20. However, in the unique construction comprising this invention provision is made for accomplishing just that. Assume, for example, assembly 10 supporting a portion of load 20 so that it is not possible to rotate the latter but it is desired to change its direction of motion, that is, rotate arrow A. First, bottom plate 16 is cycled to center underload also resulting in the centering of retaining plate 14, and then piston 24 is pressurized to raise base 18 olf the ground. Then, the whole base assembly mounted on base 18 is manually rotated, this relative rotation being taken place at the contact surfaces between pad 12 and ring 44 and between the bottom surface of groove 42 and flange rings 52 and 54 which slide around along with annular ring 44 and base 18. Thus the lubricant supplied through littings 72 and 78 facilitate this maneuver and permit it -to be accomplished with relative ease and little force. All Iof assemblies 10 supporting a single load 20, it is understood, would be pointed in parallel directions for parallel movement. To rotate load 20 itself where there are two supporting assemblies, it would be necessary merely to actuate a single one of the assemblies, change its direction lafter each cycle, so as to move it through a portion of a great circle. With practice, and With a control console for actuating the necessary steps in sequence, a single loperator can maneuver large loads into position with relative speed and accuracy.

It is thus seen that there has been provided unique apparatus for the movement of heavy loads in areas where there is insuiiicient space for the utilization of conventional movers such as cranes and fork lifts. While there has been described the inventive apparatus with various hydraulic cylinders where fluid pressure is applied as required, it is understood that the operator can be provided with a console which may be small and portable, even possibly carried in the palm of his hand so that he can pressurize the various cylinders selectively. The result is that it is possible to move heavy loads fairly rapidly, i.e. up to speeds of 200 ft. per hour, and only a single person is required to carry out the described operations.

While only a preferred embodiment of this invention has been described it is understood that the scope of this invention to be defined only by the appended claims.

I claim:

1. Compact load carrying apparatus comprising:

(a) platform means upon which said load is rested;

(b) base means for supporting said platform means;

(c) alternate means for supporting said platform means including a bottom plate, bearing means resting on s-aid bottom plate, piston means resting on said bearing means, and a cylinder formed in said platform means in which said piston means is slidable;

(d) said bearing means being slidable with respect to each of said piston means and said bottom plate;

(e) means for pressurizing said cylinder With iiuid under pressure to raise said platform means and base means thereby shifting support of said platform means to said alternate means including said piston means, bearing means and said bottom plate rendering the latter stationary; and

(f) means to slide said platform means and base means transversely on said bearing means when supported by said alternate means and to slide said bottom plate in the same direction when said cylinder is without uid under pressure and said base means is stationary to move said apparatus transversely in .a series of sequential short transverse steps -as recited.

2. The apparatus of claim 1 having means attached to said base means for pushing against said bottom plate during each transverse step, said platform `and base means being moved when said bottom plate is stationary and said bottom plate being moved when said platform and base means are stationary.

3. The apparatus of claim 2 in which said pushing means includes a fluid motor energized by fluid delivered under pressure and pusher means extending from said motor to contact said bottom plate for pushing against the latter.

4. The apparatus of claim 3 in which said pusher means includes a pair of pusher elements axially aligned and on opposite sides of said bottom plate to push alternately in opposite directions, said apparatus being movable along the axis of said pusher elements.

5. The apparatus of claim 4 `in which said base means is rotatable with respect to said platform means when the latter is supported by said alternate means for changing the direction of movement of said apparatus.

6. The apparatus of claim 5 having means to return said bearing means to the center of said bottom plate after said cylinder is relieved of liuid pressure.

7. The apparatus of claim 6 in which said return means includes a spring biased pusher arm which is retracted during movement of said platform and base means relative to said base plate.

References Cited by the Examiner UNITED STATES PATENTS 2,132,184 10/1938 Poche 180-8 3,114,425 12/1963 Adams 180-8 LEO FRIAGLIA, Primary Examiner. 

1. CONPACT LOAD CARRYING APPARATUS COMPRISING: (A) PLATFORM MEANS UPON WHICH SAID LOAD IS RESTED; (B) BASE MEANS FOR SUPPORTING SAID PLATFORM MEANS; (C) ALTERNATE MEANS FOR SUPPORTING SAID PLATFORM MEANS INCLUDING A BOTTOM PLATE, BEARING MEANS RESTING ON SAID BOTTOM PLATE, PISTON MEANS RESTING ON SAID BEARING MEANS, AND A CYLINDER FORMED IN SAID PLATFORM MEANS IN WHICH SAID PISTON MEANS IS SLIDABLE; (D) SAID BEARING MEANS BEING SLIDABLE WITH RESPECT TO EACH OF SAID PISTON MEANS AND SAID BOTTOM PLATE; (E) MEANS FOR PRESSURIZING SAID CYLINDER WITH FLUID UNDER PRESSURE TO RAISE SAID PLATFORM MEANS TO BASE MEANS THEREBY SHIFTING SUPPORT OF SAID PLATFORM 